Fabrication of a commercial aircraft typically comprises building an airframe (referred to herein as a “fuselage”) comprising a series of curved transverse ribs (referred to herein as “frames”) and longitudinal stiffeners. A frame may comprise a multiplicity of members connected end to end or may be fabricated as one piece. The outboard side of the frames is covered with an outboard wall or skin (referred to herein as an “outer skin”) made of aluminum, carbon fiber-reinforced composite material or other suitable material. The inboard side of the frames in the cabin area may similarly be partially covered with a series of curved sidewall panels that are attached to the inside of the frames, typically by screws or other fasteners. The interior sidewall panels are typically made of polymer material, and can include window frames and other structure that forms a part of the finished aircraft. Along the outboard wall and between the frames, other aircraft components such as insulation, electrical conduits, ventilation ducting, control mechanisms, and the like may be installed. Once wiring, insulation and other internal wall components are installed between the frames and inside the outboard wall, the interior sidewall panels are attached to cover the internal wall components with a durable covering that provides a pleasing appearance.
The interior sidewall panels of commercial passenger aircraft are typically configured as a number of generally curved vertical panels that extend between the floor and storage bin of the aircraft in a side-to-side manner along either interior wall of the aircraft. A decorative vertical trim strip (referred to herein as a “spline”) may be inserted between the edges of adjacent panels to cover any gap and provide a pleasing appearance to the cabin. Insulation is typically located behind the sidewall trim panels to reduce the amount of noise and vibration resulting from such external sources as the aircraft engines or turbulent air flow to the cabin. This noise and vibration is further reduced by mounting the sidewall panels against rubber shock absorbers which are also known as “shock mounts”, and which are affixed (e.g., by riveting) to the frames of the aircraft. However, the sidewall panels must be held securely against the shock mounts so that any vibration of the airframe does not cause these panels to vibrate against the frame, shock mounts, and other interior components.
Typical aircraft sidewall panels require specialized tooling and hardware for installation, such as special screws, washers, screw drivers, panel installation support aids, shims, etc. In one common arrangement, a sidewall installation involves eight fasteners that attach to their respective frame mounting brackets. Some sidewall systems include mounting hardware (e.g., screws) that is shared between adjacent panels. Other sidewall systems avoid screws and fasteners by using keyways, slotted brackets and the like.
With all of the elements of a typical sidewall installation, it can be a challenge to get the sidewall panel properly aligned rotationally, vertically and horizontally and then install all of the fasteners. For example, it is desirable to accurately adjust for the proper sidewall panel-to-center of window alignment, which may involve individually adjusting each one of multiple frame brackets, and centering the sidewall panel to align with the window before final fastening of each mounting screw. Even systems that include keyholes and brackets can involve individual adjustment of multiple brackets during installation. Consequently, typical sidewall installations involve more than one skilled worker and a significant amount of time to properly adjust the sidewall panels and install all of the fasteners. Adjusting and fastening several parts by hand is time-consuming. Moreover, even after such installations, there can be issues with gaps, wrinkles and puckers in the sidewall panel, due to internal stresses induced during the installation process and other irregularities.
Typical sidewall installations can also present challenges when removal of panels is desired. Certain aircraft maintenance and repair operations can involve the removal of one or more sidewall panels in an aircraft, in order to allow access to electrical, mechanical and other components inside the wall. With typical fastener-attached wall panels, removal of an existing panel presents a higher than desired probability of damage to the panel (perhaps resulting in costly replacement), and a higher than desired likelihood of misalignment or other defect when the panel is replaced. Panel systems that have shared fasteners between adjacent panels present other possible problems.
The present disclosure is directed toward addressing one or more of the aforementioned issues.